Underwater manipulator for wells



Dec. 29, 1964 H. L. SHATTO, JR

UNDERWATER MANIPULATOR FOR WELLS Filed Jan. 3, 1961 INVENTORI HOWARD L. SHATTO, JR.

HIS AGENT United States Patent 3,163,221 UNDERWATER NIANHULATQR FDR WELLS Howard L. Shatto, .lr., Palos Verdes, Calif, assignor to Shell Oil Company, New York, N.Y., a corporation of Delaware Filed Jan. 3, 1961, Ser. No. $0,275 8 Claims. (Cl. 166-665) This invention relates to offshore wells drilled in earth formations lying below a body of water, wherein the wellhead equipment of the well is positioned below the surface of the water. The invention pertains more particularly to a method and apparatus for manipulating equipment in the vicinity of, or which are components on an underwater wellhead.

At present, offshore wells are drilled either from stationary platforms anchored to the ocean floor, movable barges temporarily positioned on the ocean floor or from movable barges floating on the body of water in which drilling operations are being carried out. Regardless of the manner in which the wells are drilled, most wells are completed in a manner such that the outermost tubular member of the well extends upwardly from the ocean floor to a point above the surface of the water where a Wellhead assembly or Christmas tree is mounted thereon for controlling the production of the well.

Wellheads extending above the surface of the water constitute a hazard to the navigation of vessels in the area as well as constituting a structure which is readily attacked by wave action, it being Well known that the corrosive action of seawater and the air readily attack the normal steel platforms unless they are protected in a suitable manner by corrosive-resistant material. However, with the wellhead and/ or casinghead extending above the surface of the water, the flow controlling componentsof the wellhead may be readily adjusted by an operator working from a platform adjacent the wellhead structure above the surface of the water. Additionally, anyworkover or reconditioning operations carried out on the well may be readily accomplished as all of the portions of the wellhead structure which must be disassembled in order to carry out these operations, are above the surface of the water where they may be reached by maintenance crews.

Recently, however, methods and apparatus have been developed for drilling and completing oil and gas wells in the ocean floor in a manner such that after completion of the well, the wellhead assembly, including various components, such as flow control valves, is positioned beneath the surface of the water, preferably on the ocean floor. These facilities are often positioned in water depths greater than the depth at which a diver can safely and readily work. It may therefore be seen that the adjustment of any of the wellhead components from time to time, or the re-entry of a well to carry out maintenance or reconditioning work, presents a considerable problem when the wellhead assembly is positioned below the surface of the water.

It is therefore a primary object of the present invention to provide a method and apparatus for manipulating equipment in the vicinity of, or components on, a wellhead assembly positioned below the surface of the water.

A further object of the present invention is to provide a remotely-controlled manipulator device adapted to move 3,153,221 Patented Dec. 29, 71964 ice through the body of water and be temporarily secured to an underwater wellhead while being movable therearound for carrying out any of the various operations of setting, adjusting, connecting or the disconnecting of a wellhead assembly, components or associated equipment thereof.

A further object of the present invention is to provide a device adapted to be movably-positioned temporarily ona track adjacent an underwater wellhead, said device being provided with a rotatable object-engaging arm which is movable in any direction in a vertical or horizontal plane within the vicinity of the wellhead assembly.

Another object of the present invention is to provide a wellhead apparatus adapted to be positioned underwater for receiving on said apparatus and movable thereon a manipulator device adapted to engage the various components of the wellhead assembly.

Still another object of the present invention is to provide an apparatus for remotely positioning and/or connecting and/ or disconnecting drilling or production equipment in and/or on a well casing or wellhead positioned underwater.

These and other objects of this invention will be understood from the following'description taken with reference to the drawing, wherein:

FIGURE 1 is a diagrammatic view illustrating one form of a manipulator device of the present invention positioned on a wellhead or well casing extending upwardly from the ocean floor;

FIGURE 2 is a view taken along the line 22 of the wellhead manipulator device of FIGURE 1;

FIGURE 3 is an isometric view of the well casing of FIGURE 1;

FIGURE 4 is a bottom view of the manipulator device of FIGURE 1; and

FIGURE 5 is a diagrammatic view, taken in partial cross-section, of another form of drive mechanism carried by the manipulator device of the present invention.

Referring to FIGURES 1 and 3 of the drawing, a wellhead 11 is shown in the form of a conductor pipe 12 or the outermost casing string of a well drilled in the ocean floor 13, or in a formation covered by a body of water. For purposes of illustration, the wellhead 11 is shown as being positioned adjacent the ocean floor 13. However, in many circumstances, for example, where the ocean floor is very muddy, it may be desirable to position the wellhead 11 at some distance above the ocean floor 13 on the upper end ofthe conductor pipe 12,

In the foregoing description, the term wellhead is meant to include the upper end of a conductor: pipe or; well casing and any assemblage of components'either fixedly or removably secured to the top of one or more strings of pipe extending into the ocean floor, either during the drilling, completion, production, re-working, or maintenance of a well. Thus, during the drilling of a well the wellhead assembly may comprise certain components such as blow-out prevent'ers, a marine conductor pipe and seals therefor, wear sleeves, or other drilling equipment positioned on or in a well casing or conductor 7 pipe which would not be included therein'when the well was being produced; Likewise, certain wellhead compo nents of a producing well would be removed in order to carry out certain maintenance operations thereon. For illustrative purposes, the top of the wellhead 11 issshown as that of a Well being drilled without any drilling equipwellhead or V ment in place and prior to mounting well closure equip- -ment and/ or a production head thereon.

Fixedly secured .to the conductor pipe 12, preferably near the upper end thereof, is a; bearing .ring' or track 14. The track 14 preferably extends outwardly from the outer surface of the conductor pipe 12, as illustrated, but if desired, the track may be in the form of a groove cut in the outer surface of the conductor pipe 12 in the event that a thick-walled conductor pipe is used." A gear dn've ring 15 may be mounted on. the

, outersurface of, the conductor pipe 12, preferably in spaced relationship to the bearingring or track 14. The

upper surface of the gear drive ring 15 may also form a bearing ring or track similar to the upper track 14. Alternatively, the gears. of the gear ring 15 maybe cut in. the outer orlower surface of the bearing ring or track 14 4 component or device positioned or to be positioned on the well head. However, in some installations, it isappreciated that bearing ringsand gear drive rings may be I employed which do notextend entirely around the conductor pipe 12. i

'The track-mounted manipulator device 26 is shown in one form in FIGURE 1, although it is to be understood that the manipulator device, may be of any suitable form for carrying out the operations as described with regard to this invention. One suitable type of a manipulator device body is shown and described in copending patent application, Serial No. 24,558, filed April 25, 1960. The.

manipulator device shown in FIGURE 1 of the drawing comprises upper and lower telescoping body sections 40 and 41, respectively, which are preferably mounted in a rotatable and fluidtight relationship with each other.

, Suitable arrangements for mounting two body sections The bearing track 14 and/or the drive ring 15'are designed to receive and have mounted thereon a manipulator device 20 as illustrated in FIGURE 1. The manipulator device 20 is provided with at 'leastone support device for securing the manipulator device to the con,

I ductor pipe 12. As shown in FIGURE 2 of the drawing, the supporting apparatus may take the jform'of a semi circular frame 21 fixedly secured to the manipulator device20 near the upper end thereof, although preferably duplicate support frames are provided near the upper and lower ends of the manipulator device 20. The: sup- 7 port frame 21 is preferably semi-circular in shapewith:

the inner'diameter being slightly larger than the outside diameter of the conductor pipe 12. Hinged to the outer ends of the support framev 21, as by 'pivot pins 22 and 23, are a pair of grab arms 24 and 25. In their operative position the grab arms 24 and 25 are adapted to surround the conductor pipe 12 as illustrated in FIGURE 2. The grab arms 24. and 25 are provided with outwardly-extending portions 26 and 27 which are 'pivotallyi secured, as by pins 30 and 31, to linkage members 32 and 33 which may form the piston rods to, pistons (not inders 34 and 35 may be pneumatically of hydraulically operated from'a remote location or from the manipu lator device 20 itself to open and close the grab arms 24 and 25 as desired. Additionally, it is 'to' be under stood that the linkages 32 and 33 maybe electrically or =mecha'nically actuated to operate the grab arms" 24 and 25. 7

While the manipulator-device 20 with its 'grabarms 24. and 25 could be positioned 'on the conductor pipe 12 to surround the conductor pipe above the bearing ring 14 in slidingcontact therewith, the grab arms 24 and 225 are preferably provided with a series of bearing wheels 36 rotatably mounted on pin 37 that are secured to the frame 21 or the grab arms 24 and 25. As shown in FIG- URE 1, the lower grab arm consists of apaip of spaced arms 25 and 25a with a bearing wheel 36mounted therebetween on pivot pin 37. In a like'manner the upper grab arm may comprise a pair of spacedarms 25b and 25c between'which a bearing wheelf3 6a is mounted on a pivot pin 37a. .Thus the upper .bearing wheels 36a.

bear against. the upper surface of the bearing track 14 while the lower bearing wheels 36 bear against the upper surfacelfi of the gear drive ring 15;-

Any desired spacial relationship between the track 14 and ring 15 may be employed. The same spacing would be employed between the upper and lower grab arms of the manipulator device 20. While the bearing ring 14 is shown as being positioned above the gear drive ring 15 in vertical spaced relationship therewith, it is to be ufnderstood that their positions could be reversed with the gear drive ring being the higher of the two. Preferably, the bearing ring 14 and the drive ring 15 extend entirely around the conductor pipe 12 so that the ma-, nipulator device 20 can be positioned at any'pointin the circumference of the track to carry out operations on any means for rotating the manipulator device around the. In the ar-z shown) mounted withincylindersj34 and 35'. The cyla mounted on the top of the upper body section'40 of the manipulator device and a cable '43 is secured to the eye bolt for lowering the manipulator device through the water. (not shown) within the manipulator'device are electrically operated, the cable 43 may be a combined weightbearing and power-transmission cable combined in one unit. Alternatively, electric power or hydraulic fiuid couldbe transmitted through a separate conduit or con-. duit 45 into the manipulator device 20 for energizing the Various elements of the manipulator device. The prime mover apparatus, whichmay be of any 'suitableatype, employed to rotate, extend and retract the various sections of the body sections '40 "and 41 with respect to each other, or. the various arm sections 46 and 47 with respect to each other, is contained within the manipulator device 26, while the circuitry employed to energize and actuate selectively the various elements may be containedin the manipulatordevice, or in a controller at an operating base above the surface of the water, or 3 split between the two locations. Mounted preferably near or on'top of the upper body section 40 of the manipulator device 20 is one or more outwardly-extendible, inwardly-retractable, and axially-.-

rotatable arms, preferably made up of'telescoping sec tions 46 and 47. The arm is of a size and design suitable, for performing thework at the wellhead for which the present invention is designed. The" QiitWardly eX- tended arm section 47 is shown as being provided with a rotatable head 48*having a Wrench socket. 49 secured to it for turning-iin one direction or the other to manipulate bolts used on the wellhead or equipment secured thereto. The telescoping or advancing iYP arm power wrench may he of any suitable design and construction as for example similar to that shown in US. Patents 2,637,527 and 2,673,452. Alternatively,

other'tools maybe employed in place of the wrench 49x for carrying out other operations. The end of the arm 47 may beprovided with a'wrench socket (not shown) set at to the axis of the arm'47 for turning bolts or other devices whose axis is positioned normal to the; axis of the arm 47; Various tool handling devices may also be substituted for the wrench" 49, such for example, as a grapple element "as shown and described copending patent application-,Serial No. 24,558, filed.

April 25, 1960. Manipulator device 20 is provided, preferably near the bottomthereof, with prime mover drive conductorpipe as illustrated in FIGURE 1. rangement shownin FIGURE 1, the prime mover drive In the event that the prime mover means means comprises a shaft 51 extending from the body member 41 and connected to a motor (not shown) therein, for rotating a worm gear 52 which meshes with the gear drive ring 15' secured to the conductor pipe 12. The shaft and worm gear 52 may be slightly retractable to a position against the body 41 when the manipulator device 20 is lowered into place on the conductor pipe 12. After the manipulator device 21 is securely positioned on the conductor pipe 12, the worm gear 52 and shaft 51 would be extended-and rotated to engage the gear drive ring 15. It is to be understood that any other suitable gearing and drive means maybe employed for rotating the manipulator device 20 around the conductor pipe 12. 7

Alternatively, the prime mover drive means carried by the manipulator device 20 may be in the form of a friction wheel 53 which is mounted for rotation within a housing extension 54 secured to the lower end of the lower housing section 41 of the manipulator device 20 as illustrated in FIGURE 5. The friction wheel 53 is driven by any suitable gear arrangement, such as gears 55 and 56 which are rotated by a motor 57 carried in V the housing section 41. A similar motor could be employed to rotate the shaft 51 of the drive mechanism illustrated in FIGURE 1. By employing a friction-type prime mover drive mechanism as illustrated in FIGURE 5, the use of a gear drive ring 15 (FIGURE 3) on the conductor pipe 12 may be eliminated.

To observe operations being carried out near the wellhead assembly 11 by the manipulator device 29, the manipulator device 20 is provided with one or more swivel-mounted flood lights 66 and one or more television cameras 61 for lighting the area in the vicinity of the wellhead and observing operations. Both the lights 60 and the television camera 61 are remotely controlled by an operator positioned, say, at the surface of the water on an operating barge, the signal from the cameras being transmitted through cable 45.

In using the manipulator device 20 of the present invention on a wellhead designed to receive it as described hereinabove, the manipulator device 20 is lowered through the water on the cable 43 from a hoist (not shown) on a drilling barge or other vessel or'from a platform (not shown) positioned on or above the surface of the Water. Alternatively, if the manipulator device 20 is made large in size the interior of the manipulator device may act as an air chamber tending to float the device, and the buoyancy of the chamber could be altered as desired by admitting Water into it through a remotely-controlled valved opening to sink the device down to the wellhead near the ocean flood. Alternatively, the manipulator device 20 could be lowered by providing it with an independent large float chamber secured to the top of the manipulator device so that a signal could be transmitted through the cable 43 to an electrically-controlled flood valve in'the chamber for partially flooding the chamber and altering it buoyancy so as to allow-the manipulator device 20 to sink into place next to the wellhead 11. The manipulator device 20 may be guided into place by the support cable 43.

Alternatively, the manipulator device 20 may be provided with one or more propellers, preferably in the form of Kort tubes 62, 63 and 64 (FIGURE 4) which are open-ended tubes provided with propellers 65 mounted therein driven by unidirectional or reversible motors (not shown). One type of propulsion means suitable for the present apparatus is shown in US. Patents 1,344,518,

' 1,958,997, 2,583,059. Additionally, as shown in FIG- 20 around the conductor tube 12 rather than employing a worm drive 52 or the friction drive 53 as previously It may be seen.

t 6 described hereinabove. The Kort tubes may be' mounted either on top of the manipulator device" 20 or on the bottom thereof. When the manipulator device 20 is-lowered on its cable 43 into a position near the wellhead assembly 11 (FIGURE 3) by energizing the motor and one or more of the Kort tubes 62, 63 and 64 (FIGURE 4), the manipulator device 20 would be propelled through the water to its position against the -wellhead assembly as shown in FIGURE 1, at which point the grab arms 24 and 25 (FIGUREZ) would be'actuated to engage and surround the conductor pipe 12; One or more of the Kort tubes illustrated in FIGURE 4 may be energized in order to supply power to move the manipulator device 20 around the conductor pipe 12.

I claim as my invention: 1. An underwater wellhead comprising a string of pipe extending into the formation underlying a body of water, the top of said pipe being above the formation and below the surface of the water, horizontally-positioned support track means carried outwardly on said pipe near but below the top thereof, and a gear drive ring secured to the outer surface of said pipe string and extending therearound.

2. Apparatus for use at an installation positioned below the surface of a body'of water, said apparatus comprising manipulator means lowerable through the water and positionable adjacent said underwater installation,

prime mover means carried by said manipulator means for selectively moving said manipulator means relative to said underwater installation,

clamping support means carried by said manipulator means for clamping on an underwater installation to position said manipulator means adjacent thereto, said clamping support means including substantially laterally-extending arm means adapted to engage said underwater installation. laterally-extendable tool means carried by said manipulator means and positioned in a manner so as to be extended in the same direction as said clamping support means, and prime mover means for actuating said laterally-extendible tool means. i 3. The apparatus of claim 2 including horizontally-arranged positioning means carried on said underwater installation on' the outside thereof and adapted to be en-' gaged by said clamping support means.

4. The apparatus of claim 3 wherein said horizontallyarranged positioning means comprises a laterally-extending track on the outside of said underwater installation.

5. The apparatus of claim 2 including gear means fixedly secured to the outer surface of said underwater installation, and wherein said prime mover means of said manipulator means includes rotatable gear means engageable with said fixed gear means.

6. The apparatus of claim 4 wherein the arm means of said clamping support means comprises a pair of vertically-spaced clamping arms at least one of which is engageable in sliding contact above said track.

7. The apparatus of claim 2 wherein said prime mover means carried by said manipulator mean includes a m0vable friction member extending outwardly from said manipulator means for friction-ally engaging the outer surj arm means being rotatably mounted With respect to said housing and vertically and horizontally extendible there:

from, first primo mover-moans for actuating'said clamp ing support means, and second prime mover means'for- 1 B ec chi. e1 :1. Dec. 3, 1907 Ross Oc t 25,. 1932 Romano Nov; 17, 1936, Zoll Y June 1,1943, Cormany 0 May 24, 1949 Williams May 6, 1952 Solurn Mar. 3,1953 Cox et a1. Sept. 30, 1958: .Robinson June 13, 1961 Aschinger n -Mar. 13, 1962 "Reistle :May 1, 1962 Johnson 1 JulyjO, 1963-- 

1. AN UNDERWATER WELLHEAD COMPRISING A STRIP OF PIPE EXTENDING INTO THE FORMATION UNDERLYING A BODY OF WATER, THE TOP OF SAID PIPE BEING ABOVE THE FORMATION AND BELOW THE SURFACE OF THE WATER, HORIZONTALLY-POSITIONED SUPPORT TRACK MEANS CARRIED OUTWARDLY ON SAID PIPE NEAR BUT BELOW THE TOP THEREOF, AND A GEAR DRIVE RING SECURED TO THE OUTER SURFACE OF SAID PIPE STRING AND EXTENDING THEREAROUND. 